Does switching to low tar/nicotine/carbon-monoxide-yield cigarettes decrease alveolar carbon monoxide measures? A randomized controlled trial.

Assessed the effects of changing to low tar/nicotine/carbon-monoxide-(CO)-yield cigarettes on alveolar carbon monoxide over a 5–6 wk period for 40 adult chronic smokers of high tar/nicotine/CO cigarettes. Ss were assigned to either a 5-wk step-wise brand-reduction treatment or to a delayed-treatment control group. Ss were assessed for (a) resting CO body burden and CO uptake per cigarette and (b) smoking topography and rate. Although CO uptake was significantly lower after Ss smoked low tar/nicotine/CO cigarettes than after smoking their original brand, resting CO body burden did not change. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Placebo cigarettes in smoking research.

This review outlines the development and use of placebo cigarettes in smoking research. Research on effects of smoking has been disadvantaged by the lack of an adequate placebo condition. Recently, tobacco-based denicotinized cigarettes have been used in smoking research to distinguish effects of smoking due to the delivery of nicotine, other components of tobacco smoke, and the sensory process of smoking. Placebo cigarettes do not increase heart rate and blood pressure or produce electroencephalogram changes ordinarily associated with nicotine. However, placebo cigarettes reduce subjective measures of tobacco craving, desire to smoke, and tobacco withdrawal. These findings indicate that the effects of cigarette smoking are dependent on the delivery of nicotine, tar, other compounds of tobacco smoke, and the sensory stimuli. The next generation of research may begin to investigate the mechanisms that modulate these placebo effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes of smoking habits and cough in men smoking cigarettes with 30% NSM tobacco substitute

The effects of smoking cigarettes with 30% of the tobacco replaced by NSM tobacco substitute, which lowered their tar and nicotine delivery, were studied by comparing them with the effects of conventional cigarettes in a controlled crossover trial lasting 20 months. Chest symptoms, cigarette consumption, and forced expiratory volume in one second (FEV1) were measured each month. Two-hundred men began the trial and 159 completed it. The test cigarettes were acceptable to all but one of the men. In a subsample of 35 men estimates of nicotine intake were obtained from monthly analyses of cigarette stubs. On changing from NSM to control cigarettes six of the 17 men, who were accustomed to low nicotine, kept their nicotine intake down by some change in smoking habit. Before the crossover and this change in smoking habit the men smoking NSM cigarettes had a small but significant reduction of cough. Cigarettes containing 30% NSM and delivering only 1 mg of nicotine are likely to be acceptable to smokers and may reduce coughing. Further trials are needed to confirm these findings and establish what long-term effects such cigarettes may have on smokers' health.     

Behavioral and physiological effects of low-nicotine cigarettes during rapid smoking.

Compared the effects of rapid smoking using medium-tar/nicotine or low-tar/nicotine cigarettes on physiological and behavioral responses in a randomized, double-blind clinical trial with 24 Ss. Results show equivalent heart rate, blood pressure, and carbon monoxide levels after rapid smoking either low- or medium-yield cigarettes. Behavioral topography measures differed significantly when low-nicotine cigarettes were smoked. Also, Ss who did remain abstinent at subsequent follow-up showed less change in rated aversiveness during rapid smoking than Ss who did not remain abstinent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low-tar medium-nicotine cigarettes: a new approach to safer smoking

The logic of expecting people who cannot stop smoking to switch to cigarettes that have hardly any nicotine is questionable. Tar and nicotine yields of cigarettes available in Britain today correlate 0-93, and further reduction of tar intake is limited by the reluctance of smokers to tolerate similar reductions in nicotine. A new approach would be to aim at lowering tar yields of cigarettes from the present average of 18 mg to around 6 mg but maintaining nicotine yields at around 1-0 to 1-2 mg, which would be acceptable to most smokers. This approach requires that emphasis be placed on tar: nicotine ratios as well as on the absolute yields. These ratios for brands on sale in Britain today average 14-2 and range from 9-6 to 20-8. They provide an additional guide for comparing the relative harmfulness of different brands. For example, 35% of cigarette smokers in Britain smoke either Embassy Filter or Players No 6 Filter; by changing to John Player Carlton King Size they could reduce their tar intake by more than 20% without having to suffer any nicotine deprivation.     

Measures of affect and nicotine dependence predict differential response to smoking cessation treatments.

126 smokers were randomly assigned to 6-session smoking cessation treatments consisting of 1 of 2 counseling strategies (skills training or support) and 1 of 2 nicotine exposure strategies (nicotine gum or rapid smoking). Counseling and nicotine strategies were completely crossed: All 4 combinations resulted in equivalent 1-yr abstinence rates. Skills training produced higher initial cessation and more coping responses posttreatment than did support. Rapid smoking, but not nicotine gum, produced tachycardia to the taste of cigarettes posttreatment, consistent with cigarette aversion. The treatments were differentially effective among subpopulations of smokers: Ss high in pretreatment negative affect responded best to support counseling; those low in pretreatment negative affect responded best to skills training. Self-reports of pretreatment craving predicted response to the nicotine-exposure treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cigarette smoking, nicotine addiction, and relaxation.

Shock endurance was used to measure the amount of anxiety experienced in a stressful situation by nonsmokers, smokers allowed to smoke cigarettes containing low levels or moderately high levels of nicotine, and smokers not allowed to smoke. Ss were 51 university students. Smokers deprived of cigarettes and those who smoked cigarettes containing low levels of nicotine behaved more anxiously than nonsmokers and Ss allowed to smoke high-nicotine cigarettes, but the high-nicotine smokers behaved no less anxiously than nonsmokers. Results support the hypothesis that the calming effect of smoking is due to the action of nicotine in ending withdrawal symptoms in addicted smokers rather than to a sedative property of cigarette smoking. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute effects of nicotine content in cigarettes on coronary flow velocity and coronary flow reserve in men

We investigated the acute effects of smoking on coronary flow reserve in terms of the nicotine content of cigarettes in 21 smokers. Coronary flow velocity was measured with a Doppler flow wire. Subjects smoked cigarettes containing >1 mg nicotine (n = 8, group 1) or <1 mg (n = 6, group 2). Subjects in the control group mimicked smoking without a cigarette (n = 7). Coronary flow reserve decreased after smoking in group 1, but not in group 2 or the control group. This reduction may have mediated nicotine or some other unknown substances influenced by smoking.     

Blocking filter vents increases carbon monoxide levels from ultralight, but not light cigarettes

Effect of vent blocking on carbon monoxide (CO) exposure from a best-selling light cigarette was examined in 12 daily cigarette smokers. Mean CO boosts were not different from each other with (a) 0% filter vents blocked (5.0 ppm), (b) vents covered with lips (4.9 ppm), (c) 50% of vents covered with tape (4.8 ppm), and (d) vents covered with a pinch of the fingertips (4.9 ppm). A second study in another 12 smokers was conducted to replicate these findings as well as earlier findings that blocking vents doubles CO intake from 1-mg tar cigarettes. While blocking half the vents with fingers significantly increased CO boost from ultralight cigarettes (2.8 vs. 5.4 ppm, p < 0.001), it did not influence boosts from light cigarettes (6.3 vs. 6.5 ppm, p = 0.8). The lowest yield cigarettes (1 mg tar) may be special. Smoking machine simulations provide poor models of human smoke intake. It is unclear whether tar and nicotine intake from light cigarettes was influenced by vent blocking.     

Titration of nicotine intake with full-length and half-length cigarettes

Titration, the self-regulation of nicotine intake, was studied in 12 smokers by gas chromatograph assays of urinary nicotine levels. Results demonstrated that excretion of urinary nicotine in the proximal condition (half cigarette close to the filter) did not differ significantly from the whole cigarette condition; however, less nicotine was excreted in the distal condition (half cigarette farther from the filter) because of a rod filtration effect. Subjects extracted proportionately more nicotine from the half than from the whole cigarettes; titration was approximately the same in both half-cigarette conditions. On scales of strength and satisfaction, full-length cigarettes were given the highest rating, followed by proximal and then distal cigarettes.     

Effects of d-amphetamine and smoking abstinence on cue-induced cigarette craving.

In this study, the authors investigated the effects of the indirect dopamine agonist d-amphetamine (AMPH) on cue-induced cigarette craving in smokers. Abstinent or nonabstinent cigarette smokers (N=21) rated their cravings for cigarettes and for food (control) after pretreatment with AMPH (15 mg) or placebo and before and after viewing blocks of smoking-related, food-related, and neutral pictures. Before the cues were presented, AMPH increased cigarette craving and decreased food craving. Smoking and food cues increased craving for cigarettes and for food, respectively. AMPH also further increased cigarette craving (and decreased food craving) after cue presentation, but it did so regardless of cue type (food or smoking). Smoking abstinence markedly increased craving regardless of cue presentation or drug condition. These results suggest that both AMPH and smoking abstinence can increase cigarette craving, but they do not appear to specifically affect responses to conditioned smoking-related cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Blocking cigarette filter vents with lips more than doubles carbon monoxide intake from ultra-low tar cigarettes.

Light and ultra-light cigarettes achieve their lower tar, nicotine, and carbon monoxide (CO) yields on smoking machines largely by means of air-dilution vents on the filters. Previous research showed that blocking 0%, 50%, and 100% of the filter vents on a 1 mg tar cigarette with tape directly increased expired air CO levels. The present experiment extended this research by replicating the 0% blocked and 100% blocked conditions with the addition of a condition in which participants (N?=?12) were asked to block vents with their lips. Mean CO boosts for the unblocked, lip-blocked, and tape-blocked conditions were 2.7 ppm (SE?=?0.52), 6.7 ppm (SE?=? 1.0), and 12.9 ppm (SE?=?2.2), respectively. Analyses suggested that lip blockade effectively blocked approximately 50% of the filter vents. Subjective ratings of cigarette strength, harshness, and heat increased significantly as degree of vent blocking increased. Cigarette smokers need to be warned about the presence of vents and the consequences of vent blocking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Influence of Instructions and Nicotine Dose on the Subjective and Reinforcing Effects of Smoking.

Subjective and reinforcing effects of smoking a cigarette were examined within a 2 x 2 modified balanced-placebo design, which manipulated instructions about nicotine content (i.e., told regular nicotine vs. told low nicotine) and actual nicotine dose (given a regular nicotine brand vs. a denicotinized brand). Most ratings of the nicotine content and reward value of cigarettes were higher for those told regular nicotine versus told low nicotine, and for those given regular nicotine versus given low nicotine. Nicotine and instructions did not affect craving, withdrawal, or smoke-reinforced responding, but instructions affected the number of puffs earned for those given low nicotine (i.e., placebo effect). Thus, verbal information (instructions) can influence some responses to smoking consistent with the presence of placebo and antiplacebo effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The DRD4 VNTR polymorphism influences reactivity to smoking cues.

Recent research has indicated that craving for tobacco can be reliably elicited by exposure to smoking cues, suggesting that cue-elicited craving for tobacco may be a useful phenotype for research on genetic factors related to nicotine dependence. Given the potential role of dopamine in cue-elicited craving, the authors examined whether the DRD4 VNTR polymorphism is associated with cue-elicited craving for tobacco. Participants who were homozygous or heterozygous for the 7 repeat (or longer) allele were classified as DRD4 L and all other participants were classified as DRD4 S. Participants were exposed to smoking cues before smoking either high-nicotine cigarettes or control cigarettes. Analyses suggested that participants in the L group demonstrated significantly greater craving, more arousal, less positive affect, and more attention to the smoking cues than did the participants in the S group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mood influences on acute smoking responses are independent of nicotine intake and dose expectancy.

Acute responses to smoking are influenced by nicotine and by nonpharmacological factors such as nicotine dose expectancy and sensory effects of smoke inhalation. Because negative mood increases smoking reinforcement, the authors examined whether these effects may be altered by mood context. Smokers (n=200) participated in 2 sessions, negative or positive mood induction, and were randomized to 1 of 5 groups. Four groups comprised the 2×2 balanced placebo design, varying actual (0.6 mg vs. 0.05 mg yield) and expected nicotine dose (expected nicotine vs. denicotinized [denic]) of cigarettes. A fifth group was a no-smoking control. Smoking, versus not smoking, attenuated negative affect, as well as withdrawal and craving. Negative mood increased smoking reinforcement. However, neither actual nor expected nicotine dose had much influence on these responses; even those smokers receiving and expecting a denic cigarette reported attenuated negative affect. A follow-up comparison suggested that the sensory effects of smoke inhalation, but not the simple motor effects of smoking behavior, were responsible. Thus, sensory effects of smoke inhalation had a greater influence on relieving negative affect than actual or expected nicotine intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The acute effects of nicotine on positive and negative affect in adolescent smokers.

Although adolescent cigarette smoking remains a critical public health concern, little is known about the reinforcing mechanisms governing smoking in this vulnerable population. To assess predictions derived from both positive and negative reinforcement models of drug use, the authors measured the acute effects of nicotine, as administered via tobacco cigarettes, on both positive and negative affect in a group of 15- to 18-year-old smokers. A matched group of nonsmokers served as a comparison group. Findings revealed that whereas adolescents who smoked a cigarette experienced reductions in both positive and negative affect, the observed reductions in negative affect were moderated by nicotine content of the cigarette (high yield vs. denicotinized), level of nicotine dependence, level of baseline craving, and smoking expectancies pertinent to negative affect regulation. Nonsmokers experienced no change in affect over the 10-min assessment period, and no interaction effects were observed for positive affect. Overall, the findings conform to a negative reinforcement model of nicotine effects and strongly suggest that, even among young light smokers, nicotine dependence and resultant withdrawal symptomatology may serve as motivating factors governing smoking behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of transdermal nicotine patches on abstinence-induced and cue-elicited craving in cigarette smokers.

The impact of a transdermal nicotine patch on smokers' craving for cigarettes and reactivity to smoking cues was investigated. Sixty-one smokers were assessed during 2 sessions separated by 6 hr. Cue reactivity to imaginal and in vivo smoking and nonsmoking stimuli was evaluated during both sessions. During the interval between sessions, participants were abstinent from cigarettes and wore either a nicotine transdermal (21 mg) or placebo patch. In both sessions, exposure to in vivo and imaginal smoking stimuli elicited cue-specific increases in craving, negative affect, vividness, heart rate, and skin conductance. The nicotine patch attenuated craving and other effects induced by abstinence from cigarettes but had no selective impact on craving or any other reaction elicited by smoking cues. These results are discussed in terms of models of craving and clinical implications of transdermal nicotine for craving reduction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Purification and characterization of reversible sperm motility inhibitors from porcine seminal plasma

Although cigarette yields of tar and nicotine have been declining since the early 1970s, little information is available for the general population on the consequences of their use on exposure to tobacco combustion products. In a population-based sample of 298 smokers, the majority of whom were Hispanic, we examined the relationships between yields of cigarettes currently smoked and levels of salivary cotinine and end-expired carbon monoxide. Spearman correlation coefficients between the current number of cigarettes smoked and cotinine (r = 0.52) or carbon monoxide (r = 0.51) were higher than correlations between the Federal Trade Commission (FTC) nicotine data and these same markers, 0.12 and 0.05, respectively. Correlations between FTC tar and carbon monoxide yields and the biologic markers were similarly weak. In multiple linear regression models, the current number of cigarettes smoked was the most important predictor of cotinine and carbon monoxide levels (p < 0.0001). The addition of FTC tar, nicotine, or carbon monoxide to the models explained little of the variability in cotinine or carbon monoxide levels. Because FTC yields of tar and nicotine are poor predictors of exposure to tobacco combustion products, subjects' reports of cigarette brand should not be used as a primary marker of exposure in epidemiologic investigations. Furthermore, smokers need to be advised about the limitations of cigarette yield information for predicting the potential for adverse health effects of smoking.     

The influence of nicotine dose and nicotine dose expectancy on the cognitive and subjective effects of cigarette smoking.

This study investigated the independent and interactive effects of nicotine dose and nicotine dose expectancy on smoking outcomes using a 2 (given nicotine vs. placebo) × 2 (told nicotine vs. placebo) Balanced Placebo Design (BPD). Smokers (N = 148) completed the Rapid Visual Information Processing Task (RVIP) and measures of smoking urge, mood, and cigarette ratings (e.g., satisfying) after smoking a nicotine or placebo cigarette crossed with instructions that the cigarette contained either nicotine or no nicotine. Nicotine cigarettes (0.6 mg nicotine) produced better sustained attention performance than placebos as indicated by RVIP reaction time, hits, and sensitivity (A′). Nicotine cigarettes also produced better mood and greater rewarding subjective effects of the cigarettes on 11 of 11 dimensions compared to placebos. Nicotine instructions resulted in fewer RVIP false alarms, better mood, and greater rewarding subjective effects of the cigarettes on 9 of 11 dimensions compared to placebo instructions. Nicotine dose by nicotine dose expectancy interactions were also observed for urge and tension-anxiety, such that the dose expectancy manipulation produced differential effects only among those who smoked placebo cigarettes. In contrast a significant interaction for self-reported vigor-activity demonstrated that the dose expectancy manipulation produced effects only among those who smoked nicotine cigarettes. This study provides additional evidence that nicotine improves cognitive performance, and provides initial evidence that denicotinized cigarettes smoked under the guise that they contain nicotine influence cognitive performance, albeit with less robust effects than nicotine. These data may inform the development of expectancy-based interventions for tobacco dependence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)